Malware
xmrig
According to PCrisk, XMRIG is a completely legitimate open-source application that utilizes system CPUs to mine Monero cryptocurrency.
xmrig is a Windows malware family.
Background
According to PCrisk, XMRIG is itself a fully legitimate open-source program that uses a system's CPUs to mine the Monero cryptocurrency. The problem is that criminals profit by slipping the application onto machines without the owner's knowledge, a deceptive distribution tactic known as "bundling".
Typically, "bundling" delivers multiple potentially unwanted programs (PUAs) at the same time. As a result, a system infected with the XMRIG Virus is likely to have arrived alongside various adware-type applications that push intrusive advertisements and harvest sensitive data.
Source: Malpedia (Fraunhofer FKIE).